Re: [Engine-devel] 'deactivate' disk - what's the use case?

On 06/17/2012 12:44 PM, Simon Grinberg wrote: > > ----- Original Message ----- >> From: "Yaniv Kaul" <ykaul(a)redhat.com&gt; >> To: "Livnat Peer" <lpeer(a)redhat.com&gt; >> Cc: engine-devel(a)ovirt.org >> Sent: Tuesday, June 12, 2012 2:14:00 PM >> Subject: Re: [Engine-devel] 'deactivate' disk - what's the use case? >> >> On 06/12/2012 12:47 PM, Livnat Peer wrote: >>> On 12/06/12 12:40, Yaniv Kaul wrote: >>>> On 06/12/2012 12:34 PM, Itamar Heim wrote: >>>>> On 06/12/2012 12:25 PM, Yaniv Kaul wrote: >>>>>> I'm wondering what's the usefulness of having dual action of >>>>>> attach + >>>>>> activate to get a disk properly attached and working in a VM >>>>>> (and the >>>>>> deactivate and detach counterparts). >>>>>> >>>>>> The only reason I can think of is that we've annoyed the user by >>>>>> this >>>>>> useless dual action when working with storage domains in a data >>>>>> center >>>>>> for ages, and we wish to remain consistent and annoy the user in >>>>>> the >>>>>> disks scenario as well, but there may be a reason I'm not aware >>>>>> of. >>>>> deactivated is like having a disk in offline, or hot unplugging >>>>> when >>>>> you still want to retain it in the context of the vm >>>>> configuration >>>> I understand that, I just argue it's quite useless (offline can be >>>> done >>>> from within the guest OS), >>> You can deactivate the disk if for some reason it blocks the guest >>> from >>> starting. I think that if the disk not accessible the VM won't >>> start and >>> then you can deactivate the disk and start the VM. >> You can also detach it to get the same effect with one less click of >> a >> button or an API call. > And then if you did it manually for 20 VMs as a temporary measure, you'll have to re-attach it to the VMs. Will you remember to which VM you should attach each of your floating disks? You may have to now consult event log. > (And in any case you'll need better search capabilities on disk then what you have now) I still fail to see what the common use case for 'deactivate-but-not-detach' is.

I assume the description for the disk is automatically filled by engine when the disk is created attached to the VM. I'm 99.9% my assumption is naive and I'll open a RFE for it... Y. > > There are use cases to have an off-line disks, the issue is how not to annoy the user. > I think I've suggested in the past that by default: > Attach = Attach + set_Online > Detach = set_offline + Detach. > Unless explicitly stated otherwise by the user. > > Thus you do not annoy the user but still maintain the functionality. > > >> Y. >> >>> >>>> does not work that way in physical hardware >>>> (offline is a logical action within the OS), has very little value >>>> to >>>> the RHEV Admin (unless he's paranoid and afraid that the disk will >>>> become float and someone else would 'steal' it from his VM) and is >>>> annoying to require multiple actions. >>>> Y. >>>> >>>>>> TIA, >>>>>> Y. >>>>>> _______________________________________________ >>>>>> Engine-devel mailing list >>>>>> Engine-devel(a)ovirt.org >>>>>> http://lists.ovirt.org/mailman/listinfo/engine-devel >>>> _______________________________________________ >>>> Engine-devel mailing list >>>> Engine-devel(a)ovirt.org >>>> http://lists.ovirt.org/mailman/listinfo/engine-devel >> >> _______________________________________________ >> Engine-devel mailing list >> Engine-devel(a)ovirt.org >> http://lists.ovirt.org/mailman/listinfo/engine-devel >> _______________________________________________ Engine-devel mailing list Engine-devel(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel